drivers/vhost/vdpa.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Copyright (C) 2018-2020 Intel Corporation.
   4  * Copyright (C) 2020 Red Hat, Inc.
   5  *
   6  * Author: Tiwei Bie <tiwei.bie@intel.com>
   7  *         Jason Wang <jasowang@redhat.com>
   8  *
   9  * Thanks Michael S. Tsirkin for the valuable comments and
  10  * suggestions.  And thanks to Cunming Liang and Zhihong Wang for all
  11  * their supports.
  12  */
  13
  14 #include <linux/kernel.h>
  15 #include <linux/module.h>
  16 #include <linux/cdev.h>
  17 #include <linux/device.h>
  18 #include <linux/mm.h>
  19 #include <linux/iommu.h>
  20 #include <linux/uuid.h>
  21 #include <linux/vdpa.h>
  22 #include <linux/nospec.h>
  23 #include <linux/vhost.h>
  24 #include <linux/virtio_net.h>
  25
  26 #include "vhost.h"
  27
  28 enum {
  29         VHOST_VDPA_BACKEND_FEATURES =
  30         (1ULL << VHOST_BACKEND_F_IOTLB_MSG_V2) |
  31         (1ULL << VHOST_BACKEND_F_IOTLB_BATCH),
  32 };
  33
  34 #define VHOST_VDPA_DEV_MAX (1U << MINORBITS)
  35
  36 struct vhost_vdpa {
  37         struct vhost_dev vdev;
  38         struct iommu_domain *domain;
  39         struct vhost_virtqueue *vqs;
  40         struct completion completion;
  41         struct vdpa_device *vdpa;
  42         struct device dev;
  43         struct cdev cdev;
  44         atomic_t opened;
  45         int nvqs;
  46         int virtio_id;
  47         int minor;
  48         struct eventfd_ctx *config_ctx;
  49         int in_batch;
  50         struct vdpa_iova_range range;
  51 };
  52
  53 static DEFINE_IDA(vhost_vdpa_ida);
  54
  55 static dev_t vhost_vdpa_major;
  56
  57 static void handle_vq_kick(struct vhost_work *work)
  58 {
  59         struct vhost_virtqueue *vq = container_of(work, struct vhost_virtqueue,
  60                                                   poll.work);
  61         struct vhost_vdpa *v = container_of(vq->dev, struct vhost_vdpa, vdev);
  62         const struct vdpa_config_ops *ops = v->vdpa->config;
  63
  64         ops->kick_vq(v->vdpa, vq - v->vqs);
  65 }
  66
  67 static irqreturn_t vhost_vdpa_virtqueue_cb(void *private)
  68 {
  69         struct vhost_virtqueue *vq = private;
  70         struct eventfd_ctx *call_ctx = vq->call_ctx.ctx;
  71
  72         if (call_ctx)
  73                 eventfd_signal(call_ctx, 1);
  74
  75         return IRQ_HANDLED;
  76 }
  77
  78 static irqreturn_t vhost_vdpa_config_cb(void *private)
  79 {
  80         struct vhost_vdpa *v = private;
  81         struct eventfd_ctx *config_ctx = v->config_ctx;
  82
  83         if (config_ctx)
  84                 eventfd_signal(config_ctx, 1);
  85
  86         return IRQ_HANDLED;
  87 }
  88
  89 static void vhost_vdpa_setup_vq_irq(struct vhost_vdpa *v, u16 qid)
  90 {
  91         struct vhost_virtqueue *vq = &v->vqs[qid];
  92         const struct vdpa_config_ops *ops = v->vdpa->config;
  93         struct vdpa_device *vdpa = v->vdpa;
  94         int ret, irq;
  95
  96         if (!ops->get_vq_irq)
  97                 return;
  98
  99         irq = ops->get_vq_irq(vdpa, qid);
 100         irq_bypass_unregister_producer(&vq->call_ctx.producer);
 101         if (!vq->call_ctx.ctx || irq < 0)
 102                 return;
 103
 104         vq->call_ctx.producer.token = vq->call_ctx.ctx;
 105         vq->call_ctx.producer.irq = irq;
 106         ret = irq_bypass_register_producer(&vq->call_ctx.producer);
 107         if (unlikely(ret))
 108                 dev_info(&v->dev, "vq %u, irq bypass producer (token %p) registration fails, ret =  %d\n",
 109                          qid, vq->call_ctx.producer.token, ret);
 110 }
 111
 112 static void vhost_vdpa_unsetup_vq_irq(struct vhost_vdpa *v, u16 qid)
 113 {
 114         struct vhost_virtqueue *vq = &v->vqs[qid];
 115
 116         irq_bypass_unregister_producer(&vq->call_ctx.producer);
 117 }
 118
 119 static void vhost_vdpa_reset(struct vhost_vdpa *v)
 120 {
 121         struct vdpa_device *vdpa = v->vdpa;
 122
 123         vdpa_reset(vdpa);
 124         v->in_batch = 0;
 125 }
 126
 127 static long vhost_vdpa_get_device_id(struct vhost_vdpa *v, u8 __user *argp)
 128 {
 129         struct vdpa_device *vdpa = v->vdpa;
 130         const struct vdpa_config_ops *ops = vdpa->config;
 131         u32 device_id;
 132
 133         device_id = ops->get_device_id(vdpa);
 134
 135         if (copy_to_user(argp, &device_id, sizeof(device_id)))
 136                 return -EFAULT;
 137
 138         return 0;
 139 }
 140
 141 static long vhost_vdpa_get_status(struct vhost_vdpa *v, u8 __user *statusp)
 142 {
 143         struct vdpa_device *vdpa = v->vdpa;
 144         const struct vdpa_config_ops *ops = vdpa->config;
 145         u8 status;
 146
 147         status = ops->get_status(vdpa);
 148
 149         if (copy_to_user(statusp, &status, sizeof(status)))
 150                 return -EFAULT;
 151
 152         return 0;
 153 }
 154
 155 static long vhost_vdpa_set_status(struct vhost_vdpa *v, u8 __user *statusp)
 156 {
 157         struct vdpa_device *vdpa = v->vdpa;
 158         const struct vdpa_config_ops *ops = vdpa->config;
 159         u8 status, status_old;
 160         int nvqs = v->nvqs;
 161         u16 i;
 162
 163         if (copy_from_user(&status, statusp, sizeof(status)))
 164                 return -EFAULT;
 165
 166         status_old = ops->get_status(vdpa);
 167
 168         /*
 169          * Userspace shouldn't remove status bits unless reset the
 170          * status to 0.
 171          */
 172         if (status != 0 && (ops->get_status(vdpa) & ~status) != 0)
 173                 return -EINVAL;
 174
 175         ops->set_status(vdpa, status);
 176
 177         if ((status & VIRTIO_CONFIG_S_DRIVER_OK) && !(status_old & VIRTIO_CONFIG_S_DRIVER_OK))
 178                 for (i = 0; i < nvqs; i++)
 179                         vhost_vdpa_setup_vq_irq(v, i);
 180
 181         if ((status_old & VIRTIO_CONFIG_S_DRIVER_OK) && !(status & VIRTIO_CONFIG_S_DRIVER_OK))
 182                 for (i = 0; i < nvqs; i++)
 183                         vhost_vdpa_unsetup_vq_irq(v, i);
 184
 185         return 0;
 186 }
 187
 188 static int vhost_vdpa_config_validate(struct vhost_vdpa *v,
 189                                       struct vhost_vdpa_config *c)
 190 {
 191         long size = 0;
 192
 193         switch (v->virtio_id) {
 194         case VIRTIO_ID_NET:
 195                 size = sizeof(struct virtio_net_config);
 196                 break;
 197         }
 198
 199         if (c->len == 0)
 200                 return -EINVAL;
 201
 202         if (c->len > size - c->off)
 203                 return -E2BIG;
 204
 205         return 0;
 206 }
 207
 208 static long vhost_vdpa_get_config(struct vhost_vdpa *v,
 209                                   struct vhost_vdpa_config __user *c)
 210 {
 211         struct vdpa_device *vdpa = v->vdpa;
 212         struct vhost_vdpa_config config;
 213         unsigned long size = offsetof(struct vhost_vdpa_config, buf);
 214         u8 *buf;
 215
 216         if (copy_from_user(&config, c, size))
 217                 return -EFAULT;
 218         if (vhost_vdpa_config_validate(v, &config))
 219                 return -EINVAL;
 220         buf = kvzalloc(config.len, GFP_KERNEL);
 221         if (!buf)
 222                 return -ENOMEM;
 223
 224         vdpa_get_config(vdpa, config.off, buf, config.len);
 225
 226         if (copy_to_user(c->buf, buf, config.len)) {
 227                 kvfree(buf);
 228                 return -EFAULT;
 229         }
 230
 231         kvfree(buf);
 232         return 0;
 233 }
 234
 235 static long vhost_vdpa_set_config(struct vhost_vdpa *v,
 236                                   struct vhost_vdpa_config __user *c)
 237 {
 238         struct vdpa_device *vdpa = v->vdpa;
 239         const struct vdpa_config_ops *ops = vdpa->config;
 240         struct vhost_vdpa_config config;
 241         unsigned long size = offsetof(struct vhost_vdpa_config, buf);
 242         u8 *buf;
 243
 244         if (copy_from_user(&config, c, size))
 245                 return -EFAULT;
 246         if (vhost_vdpa_config_validate(v, &config))
 247                 return -EINVAL;
 248         buf = kvzalloc(config.len, GFP_KERNEL);
 249         if (!buf)
 250                 return -ENOMEM;
 251
 252         if (copy_from_user(buf, c->buf, config.len)) {
 253                 kvfree(buf);
 254                 return -EFAULT;
 255         }
 256
 257         ops->set_config(vdpa, config.off, buf, config.len);
 258
 259         kvfree(buf);
 260         return 0;
 261 }
 262
 263 static long vhost_vdpa_get_features(struct vhost_vdpa *v, u64 __user *featurep)
 264 {
 265         struct vdpa_device *vdpa = v->vdpa;
 266         const struct vdpa_config_ops *ops = vdpa->config;
 267         u64 features;
 268
 269         features = ops->get_features(vdpa);
 270
 271         if (copy_to_user(featurep, &features, sizeof(features)))
 272                 return -EFAULT;
 273
 274         return 0;
 275 }
 276
 277 static long vhost_vdpa_set_features(struct vhost_vdpa *v, u64 __user *featurep)
 278 {
 279         struct vdpa_device *vdpa = v->vdpa;
 280         const struct vdpa_config_ops *ops = vdpa->config;
 281         u64 features;
 282
 283         /*
 284          * It's not allowed to change the features after they have
 285          * been negotiated.
 286          */
 287         if (ops->get_status(vdpa) & VIRTIO_CONFIG_S_FEATURES_OK)
 288                 return -EBUSY;
 289
 290         if (copy_from_user(&features, featurep, sizeof(features)))
 291                 return -EFAULT;
 292
 293         if (vdpa_set_features(vdpa, features))
 294                 return -EINVAL;
 295
 296         return 0;
 297 }
 298
 299 static long vhost_vdpa_get_vring_num(struct vhost_vdpa *v, u16 __user *argp)
 300 {
 301         struct vdpa_device *vdpa = v->vdpa;
 302         const struct vdpa_config_ops *ops = vdpa->config;
 303         u16 num;
 304
 305         num = ops->get_vq_num_max(vdpa);
 306
 307         if (copy_to_user(argp, &num, sizeof(num)))
 308                 return -EFAULT;
 309
 310         return 0;
 311 }
 312
 313 static void vhost_vdpa_config_put(struct vhost_vdpa *v)
 314 {
 315         if (v->config_ctx)
 316                 eventfd_ctx_put(v->config_ctx);
 317 }
 318
 319 static long vhost_vdpa_set_config_call(struct vhost_vdpa *v, u32 __user *argp)
 320 {
 321         struct vdpa_callback cb;
 322         int fd;
 323         struct eventfd_ctx *ctx;
 324
 325         cb.callback = vhost_vdpa_config_cb;
 326         cb.private = v->vdpa;
 327         if (copy_from_user(&fd, argp, sizeof(fd)))
 328                 return  -EFAULT;
 329
 330         ctx = fd == VHOST_FILE_UNBIND ? NULL : eventfd_ctx_fdget(fd);
 331         swap(ctx, v->config_ctx);
 332
 333         if (!IS_ERR_OR_NULL(ctx))
 334                 eventfd_ctx_put(ctx);
 335
 336         if (IS_ERR(v->config_ctx))
 337                 return PTR_ERR(v->config_ctx);
 338
 339         v->vdpa->config->set_config_cb(v->vdpa, &cb);
 340
 341         return 0;
 342 }
 343
 344 static long vhost_vdpa_get_iova_range(struct vhost_vdpa *v, u32 __user *argp)
 345 {
 346         struct vhost_vdpa_iova_range range = {
 347                 .first = v->range.first,
 348                 .last = v->range.last,
 349         };
 350
 351         if (copy_to_user(argp, &range, sizeof(range)))
 352                 return -EFAULT;
 353         return 0;
 354 }
 355
 356 static long vhost_vdpa_vring_ioctl(struct vhost_vdpa *v, unsigned int cmd,
 357                                    void __user *argp)
 358 {
 359         struct vdpa_device *vdpa = v->vdpa;
 360         const struct vdpa_config_ops *ops = vdpa->config;
 361         struct vdpa_vq_state vq_state;
 362         struct vdpa_callback cb;
 363         struct vhost_virtqueue *vq;
 364         struct vhost_vring_state s;
 365         u32 idx;
 366         long r;
 367
 368         r = get_user(idx, (u32 __user *)argp);
 369         if (r < 0)
 370                 return r;
 371
 372         if (idx >= v->nvqs)
 373                 return -ENOBUFS;
 374
 375         idx = array_index_nospec(idx, v->nvqs);
 376         vq = &v->vqs[idx];
 377
 378         switch (cmd) {
 379         case VHOST_VDPA_SET_VRING_ENABLE:
 380                 if (copy_from_user(&s, argp, sizeof(s)))
 381                         return -EFAULT;
 382                 ops->set_vq_ready(vdpa, idx, s.num);
 383                 return 0;
 384         case VHOST_GET_VRING_BASE:
 385                 r = ops->get_vq_state(v->vdpa, idx, &vq_state);
 386                 if (r)
 387                         return r;
 388
 389                 vq->last_avail_idx = vq_state.avail_index;
 390                 break;
 391         }
 392
 393         r = vhost_vring_ioctl(&v->vdev, cmd, argp);
 394         if (r)
 395                 return r;
 396
 397         switch (cmd) {
 398         case VHOST_SET_VRING_ADDR:
 399                 if (ops->set_vq_address(vdpa, idx,
 400                                         (u64)(uintptr_t)vq->desc,
 401                                         (u64)(uintptr_t)vq->avail,
 402                                         (u64)(uintptr_t)vq->used))
 403                         r = -EINVAL;
 404                 break;
 405
 406         case VHOST_SET_VRING_BASE:
 407                 vq_state.avail_index = vq->last_avail_idx;
 408                 if (ops->set_vq_state(vdpa, idx, &vq_state))
 409                         r = -EINVAL;
 410                 break;
 411
 412         case VHOST_SET_VRING_CALL:
 413                 if (vq->call_ctx.ctx) {
 414                         cb.callback = vhost_vdpa_virtqueue_cb;
 415                         cb.private = vq;
 416                 } else {
 417                         cb.callback = NULL;
 418                         cb.private = NULL;
 419                 }
 420                 ops->set_vq_cb(vdpa, idx, &cb);
 421                 vhost_vdpa_setup_vq_irq(v, idx);
 422                 break;
 423
 424         case VHOST_SET_VRING_NUM:
 425                 ops->set_vq_num(vdpa, idx, vq->num);
 426                 break;
 427         }
 428
 429         return r;
 430 }
 431
 432 static long vhost_vdpa_unlocked_ioctl(struct file *filep,
 433                                       unsigned int cmd, unsigned long arg)
 434 {
 435         struct vhost_vdpa *v = filep->private_data;
 436         struct vhost_dev *d = &v->vdev;
 437         void __user *argp = (void __user *)arg;
 438         u64 __user *featurep = argp;
 439         u64 features;
 440         long r = 0;
 441
 442         if (cmd == VHOST_SET_BACKEND_FEATURES) {
 443                 if (copy_from_user(&features, featurep, sizeof(features)))
 444                         return -EFAULT;
 445                 if (features & ~VHOST_VDPA_BACKEND_FEATURES)
 446                         return -EOPNOTSUPP;
 447                 vhost_set_backend_features(&v->vdev, features);
 448                 return 0;
 449         }
 450
 451         mutex_lock(&d->mutex);
 452
 453         switch (cmd) {
 454         case VHOST_VDPA_GET_DEVICE_ID:
 455                 r = vhost_vdpa_get_device_id(v, argp);
 456                 break;
 457         case VHOST_VDPA_GET_STATUS:
 458                 r = vhost_vdpa_get_status(v, argp);
 459                 break;
 460         case VHOST_VDPA_SET_STATUS:
 461                 r = vhost_vdpa_set_status(v, argp);
 462                 break;
 463         case VHOST_VDPA_GET_CONFIG:
 464                 r = vhost_vdpa_get_config(v, argp);
 465                 break;
 466         case VHOST_VDPA_SET_CONFIG:
 467                 r = vhost_vdpa_set_config(v, argp);
 468                 break;
 469         case VHOST_GET_FEATURES:
 470                 r = vhost_vdpa_get_features(v, argp);
 471                 break;
 472         case VHOST_SET_FEATURES:
 473                 r = vhost_vdpa_set_features(v, argp);
 474                 break;
 475         case VHOST_VDPA_GET_VRING_NUM:
 476                 r = vhost_vdpa_get_vring_num(v, argp);
 477                 break;
 478         case VHOST_SET_LOG_BASE:
 479         case VHOST_SET_LOG_FD:
 480                 r = -ENOIOCTLCMD;
 481                 break;
 482         case VHOST_VDPA_SET_CONFIG_CALL:
 483                 r = vhost_vdpa_set_config_call(v, argp);
 484                 break;
 485         case VHOST_GET_BACKEND_FEATURES:
 486                 features = VHOST_VDPA_BACKEND_FEATURES;
 487                 if (copy_to_user(featurep, &features, sizeof(features)))
 488                         r = -EFAULT;
 489                 break;
 490         case VHOST_VDPA_GET_IOVA_RANGE:
 491                 r = vhost_vdpa_get_iova_range(v, argp);
 492                 break;
 493         default:
 494                 r = vhost_dev_ioctl(&v->vdev, cmd, argp);
 495                 if (r == -ENOIOCTLCMD)
 496                         r = vhost_vdpa_vring_ioctl(v, cmd, argp);
 497                 break;
 498         }
 499
 500         mutex_unlock(&d->mutex);
 501         return r;
 502 }
 503
 504 static void vhost_vdpa_iotlb_unmap(struct vhost_vdpa *v, u64 start, u64 last)
 505 {
 506         struct vhost_dev *dev = &v->vdev;
 507         struct vhost_iotlb *iotlb = dev->iotlb;
 508         struct vhost_iotlb_map *map;
 509         struct page *page;
 510         unsigned long pfn, pinned;
 511
 512         while ((map = vhost_iotlb_itree_first(iotlb, start, last)) != NULL) {
 513                 pinned = map->size >> PAGE_SHIFT;
 514                 for (pfn = map->addr >> PAGE_SHIFT;
 515                      pinned > 0; pfn++, pinned--) {
 516                         page = pfn_to_page(pfn);
 517                         if (map->perm & VHOST_ACCESS_WO)
 518                                 set_page_dirty_lock(page);
 519                         unpin_user_page(page);
 520                 }
 521                 atomic64_sub(map->size >> PAGE_SHIFT, &dev->mm->pinned_vm);
 522                 vhost_iotlb_map_free(iotlb, map);
 523         }
 524 }
 525
 526 static void vhost_vdpa_iotlb_free(struct vhost_vdpa *v)
 527 {
 528         struct vhost_dev *dev = &v->vdev;
 529
 530         vhost_vdpa_iotlb_unmap(v, 0ULL, 0ULL - 1);
 531         kfree(dev->iotlb);
 532         dev->iotlb = NULL;
 533 }
 534
 535 static int perm_to_iommu_flags(u32 perm)
 536 {
 537         int flags = 0;
 538
 539         switch (perm) {
 540         case VHOST_ACCESS_WO:
 541                 flags |= IOMMU_WRITE;
 542                 break;
 543         case VHOST_ACCESS_RO:
 544                 flags |= IOMMU_READ;
 545                 break;
 546         case VHOST_ACCESS_RW:
 547                 flags |= (IOMMU_WRITE | IOMMU_READ);
 548                 break;
 549         default:
 550                 WARN(1, "invalidate vhost IOTLB permission\n");
 551                 break;
 552         }
 553
 554         return flags | IOMMU_CACHE;
 555 }
 556
 557 static int vhost_vdpa_map(struct vhost_vdpa *v,
 558                           u64 iova, u64 size, u64 pa, u32 perm)
 559 {
 560         struct vhost_dev *dev = &v->vdev;
 561         struct vdpa_device *vdpa = v->vdpa;
 562         const struct vdpa_config_ops *ops = vdpa->config;
 563         int r = 0;
 564
 565         r = vhost_iotlb_add_range(dev->iotlb, iova, iova + size - 1,
 566                                   pa, perm);
 567         if (r)
 568                 return r;
 569
 570         if (ops->dma_map) {
 571                 r = ops->dma_map(vdpa, iova, size, pa, perm);
 572         } else if (ops->set_map) {
 573                 if (!v->in_batch)
 574                         r = ops->set_map(vdpa, dev->iotlb);
 575         } else {
 576                 r = iommu_map(v->domain, iova, pa, size,
 577                               perm_to_iommu_flags(perm));
 578         }
 579
 580         if (r)
 581                 vhost_iotlb_del_range(dev->iotlb, iova, iova + size - 1);
 582         else
 583                 atomic64_add(size >> PAGE_SHIFT, &dev->mm->pinned_vm);
 584
 585         return r;
 586 }
 587
 588 static void vhost_vdpa_unmap(struct vhost_vdpa *v, u64 iova, u64 size)
 589 {
 590         struct vhost_dev *dev = &v->vdev;
 591         struct vdpa_device *vdpa = v->vdpa;
 592         const struct vdpa_config_ops *ops = vdpa->config;
 593
 594         vhost_vdpa_iotlb_unmap(v, iova, iova + size - 1);
 595
 596         if (ops->dma_map) {
 597                 ops->dma_unmap(vdpa, iova, size);
 598         } else if (ops->set_map) {
 599                 if (!v->in_batch)
 600                         ops->set_map(vdpa, dev->iotlb);
 601         } else {
 602                 iommu_unmap(v->domain, iova, size);
 603         }
 604 }
 605
 606 static int vhost_vdpa_process_iotlb_update(struct vhost_vdpa *v,
 607                                            struct vhost_iotlb_msg *msg)
 608 {
 609         struct vhost_dev *dev = &v->vdev;
 610         struct vhost_iotlb *iotlb = dev->iotlb;
 611         struct page **page_list;
 612         unsigned long list_size = PAGE_SIZE / sizeof(struct page *);
 613         unsigned int gup_flags = FOLL_LONGTERM;
 614         unsigned long npages, cur_base, map_pfn, last_pfn = 0;
 615         unsigned long lock_limit, sz2pin, nchunks, i;
 616         u64 iova = msg->iova;
 617         long pinned;
 618         int ret = 0;
 619
 620         if (msg->iova < v->range.first ||
 621             msg->iova + msg->size - 1 > v->range.last)
 622                 return -EINVAL;
 623
 624         if (vhost_iotlb_itree_first(iotlb, msg->iova,
 625                                     msg->iova + msg->size - 1))
 626                 return -EEXIST;
 627
 628         /* Limit the use of memory for bookkeeping */
 629         page_list = (struct page **) __get_free_page(GFP_KERNEL);
 630         if (!page_list)
 631                 return -ENOMEM;
 632
 633         if (msg->perm & VHOST_ACCESS_WO)
 634                 gup_flags |= FOLL_WRITE;
 635
 636         npages = PAGE_ALIGN(msg->size + (iova & ~PAGE_MASK)) >> PAGE_SHIFT;
 637         if (!npages) {
 638                 ret = -EINVAL;
 639                 goto free;
 640         }
 641
 642         mmap_read_lock(dev->mm);
 643
 644         lock_limit = rlimit(RLIMIT_MEMLOCK) >> PAGE_SHIFT;
 645         if (npages + atomic64_read(&dev->mm->pinned_vm) > lock_limit) {
 646                 ret = -ENOMEM;
 647                 goto unlock;
 648         }
 649
 650         cur_base = msg->uaddr & PAGE_MASK;
 651         iova &= PAGE_MASK;
 652         nchunks = 0;
 653
 654         while (npages) {
 655                 sz2pin = min_t(unsigned long, npages, list_size);
 656                 pinned = pin_user_pages(cur_base, sz2pin,
 657                                         gup_flags, page_list, NULL);
 658                 if (sz2pin != pinned) {
 659                         if (pinned < 0) {
 660                                 ret = pinned;
 661                         } else {
 662                                 unpin_user_pages(page_list, pinned);
 663                                 ret = -ENOMEM;
 664                         }
 665                         goto out;
 666                 }
 667                 nchunks++;
 668
 669                 if (!last_pfn)
 670                         map_pfn = page_to_pfn(page_list[0]);
 671
 672                 for (i = 0; i < pinned; i++) {
 673                         unsigned long this_pfn = page_to_pfn(page_list[i]);
 674                         u64 csize;
 675
 676                         if (last_pfn && (this_pfn != last_pfn + 1)) {
 677                                 /* Pin a contiguous chunk of memory */
 678                                 csize = (last_pfn - map_pfn + 1) << PAGE_SHIFT;
 679                                 ret = vhost_vdpa_map(v, iova, csize,
 680                                                      map_pfn << PAGE_SHIFT,
 681                                                      msg->perm);
 682                                 if (ret) {
 683                                         /*
 684                                          * Unpin the pages that are left unmapped
 685                                          * from this point on in the current
 686                                          * page_list. The remaining outstanding
 687                                          * ones which may stride across several
 688                                          * chunks will be covered in the common
 689                                          * error path subsequently.
 690                                          */
 691                                         unpin_user_pages(&page_list[i],
 692                                                          pinned - i);
 693                                         goto out;
 694                                 }
 695
 696                                 map_pfn = this_pfn;
 697                                 iova += csize;
 698                                 nchunks = 0;
 699                         }
 700
 701                         last_pfn = this_pfn;
 702                 }
 703
 704                 cur_base += pinned << PAGE_SHIFT;
 705                 npages -= pinned;
 706         }
 707
 708         /* Pin the rest chunk */
 709         ret = vhost_vdpa_map(v, iova, (last_pfn - map_pfn + 1) << PAGE_SHIFT,
 710                              map_pfn << PAGE_SHIFT, msg->perm);
 711 out:
 712         if (ret) {
 713                 if (nchunks) {
 714                         unsigned long pfn;
 715
 716                         /*
 717                          * Unpin the outstanding pages which are yet to be
 718                          * mapped but haven't due to vdpa_map() or
 719                          * pin_user_pages() failure.
 720                          *
 721                          * Mapped pages are accounted in vdpa_map(), hence
 722                          * the corresponding unpinning will be handled by
 723                          * vdpa_unmap().
 724                          */
 725                         WARN_ON(!last_pfn);
 726                         for (pfn = map_pfn; pfn <= last_pfn; pfn++)
 727                                 unpin_user_page(pfn_to_page(pfn));
 728                 }
 729                 vhost_vdpa_unmap(v, msg->iova, msg->size);
 730         }
 731 unlock:
 732         mmap_read_unlock(dev->mm);
 733 free:
 734         free_page((unsigned long)page_list);
 735         return ret;
 736 }
 737
 738 static int vhost_vdpa_process_iotlb_msg(struct vhost_dev *dev,
 739                                         struct vhost_iotlb_msg *msg)
 740 {
 741         struct vhost_vdpa *v = container_of(dev, struct vhost_vdpa, vdev);
 742         struct vdpa_device *vdpa = v->vdpa;
 743         const struct vdpa_config_ops *ops = vdpa->config;
 744         int r = 0;
 745
 746         r = vhost_dev_check_owner(dev);
 747         if (r)
 748                 return r;
 749
 750         switch (msg->type) {
 751         case VHOST_IOTLB_UPDATE:
 752                 r = vhost_vdpa_process_iotlb_update(v, msg);
 753                 break;
 754         case VHOST_IOTLB_INVALIDATE:
 755                 vhost_vdpa_unmap(v, msg->iova, msg->size);
 756                 break;
 757         case VHOST_IOTLB_BATCH_BEGIN:
 758                 v->in_batch = true;
 759                 break;
 760         case VHOST_IOTLB_BATCH_END:
 761                 if (v->in_batch && ops->set_map)
 762                         ops->set_map(vdpa, dev->iotlb);
 763                 v->in_batch = false;
 764                 break;
 765         default:
 766                 r = -EINVAL;
 767                 break;
 768         }
 769
 770         return r;
 771 }
 772
 773 static ssize_t vhost_vdpa_chr_write_iter(struct kiocb *iocb,
 774                                          struct iov_iter *from)
 775 {
 776         struct file *file = iocb->ki_filp;
 777         struct vhost_vdpa *v = file->private_data;
 778         struct vhost_dev *dev = &v->vdev;
 779
 780         return vhost_chr_write_iter(dev, from);
 781 }
 782
 783 static int vhost_vdpa_alloc_domain(struct vhost_vdpa *v)
 784 {
 785         struct vdpa_device *vdpa = v->vdpa;
 786         const struct vdpa_config_ops *ops = vdpa->config;
 787         struct device *dma_dev = vdpa_get_dma_dev(vdpa);
 788         struct bus_type *bus;
 789         int ret;
 790
 791         /* Device want to do DMA by itself */
 792         if (ops->set_map || ops->dma_map)
 793                 return 0;
 794
 795         bus = dma_dev->bus;
 796         if (!bus)
 797                 return -EFAULT;
 798
 799         if (!iommu_capable(bus, IOMMU_CAP_CACHE_COHERENCY))
 800                 return -ENOTSUPP;
 801
 802         v->domain = iommu_domain_alloc(bus);
 803         if (!v->domain)
 804                 return -EIO;
 805
 806         ret = iommu_attach_device(v->domain, dma_dev);
 807         if (ret)
 808                 goto err_attach;
 809
 810         return 0;
 811
 812 err_attach:
 813         iommu_domain_free(v->domain);
 814         return ret;
 815 }
 816
 817 static void vhost_vdpa_free_domain(struct vhost_vdpa *v)
 818 {
 819         struct vdpa_device *vdpa = v->vdpa;
 820         struct device *dma_dev = vdpa_get_dma_dev(vdpa);
 821
 822         if (v->domain) {
 823                 iommu_detach_device(v->domain, dma_dev);
 824                 iommu_domain_free(v->domain);
 825         }
 826
 827         v->domain = NULL;
 828 }
 829
 830 static void vhost_vdpa_set_iova_range(struct vhost_vdpa *v)
 831 {
 832         struct vdpa_iova_range *range = &v->range;
 833         struct iommu_domain_geometry geo;
 834         struct vdpa_device *vdpa = v->vdpa;
 835         const struct vdpa_config_ops *ops = vdpa->config;
 836
 837         if (ops->get_iova_range) {
 838                 *range = ops->get_iova_range(vdpa);
 839         } else if (v->domain &&
 840                    !iommu_domain_get_attr(v->domain,
 841                    DOMAIN_ATTR_GEOMETRY, &geo) &&
 842                    geo.force_aperture) {
 843                 range->first = geo.aperture_start;
 844                 range->last = geo.aperture_end;
 845         } else {
 846                 range->first = 0;
 847                 range->last = ULLONG_MAX;
 848         }
 849 }
 850
 851 static int vhost_vdpa_open(struct inode *inode, struct file *filep)
 852 {
 853         struct vhost_vdpa *v;
 854         struct vhost_dev *dev;
 855         struct vhost_virtqueue **vqs;
 856         int nvqs, i, r, opened;
 857
 858         v = container_of(inode->i_cdev, struct vhost_vdpa, cdev);
 859
 860         opened = atomic_cmpxchg(&v->opened, 0, 1);
 861         if (opened)
 862                 return -EBUSY;
 863
 864         nvqs = v->nvqs;
 865         vhost_vdpa_reset(v);
 866
 867         vqs = kmalloc_array(nvqs, sizeof(*vqs), GFP_KERNEL);
 868         if (!vqs) {
 869                 r = -ENOMEM;
 870                 goto err;
 871         }
 872
 873         dev = &v->vdev;
 874         for (i = 0; i < nvqs; i++) {
 875                 vqs[i] = &v->vqs[i];
 876                 vqs[i]->handle_kick = handle_vq_kick;
 877         }
 878         vhost_dev_init(dev, vqs, nvqs, 0, 0, 0, false,
 879                        vhost_vdpa_process_iotlb_msg);
 880
 881         dev->iotlb = vhost_iotlb_alloc(0, 0);
 882         if (!dev->iotlb) {
 883                 r = -ENOMEM;
 884                 goto err_init_iotlb;
 885         }
 886
 887         r = vhost_vdpa_alloc_domain(v);
 888         if (r)
 889                 goto err_init_iotlb;
 890
 891         vhost_vdpa_set_iova_range(v);
 892
 893         filep->private_data = v;
 894
 895         return 0;
 896
 897 err_init_iotlb:
 898         vhost_dev_cleanup(&v->vdev);
 899         kfree(vqs);
 900 err:
 901         atomic_dec(&v->opened);
 902         return r;
 903 }
 904
 905 static void vhost_vdpa_clean_irq(struct vhost_vdpa *v)
 906 {
 907         struct vhost_virtqueue *vq;
 908         int i;
 909
 910         for (i = 0; i < v->nvqs; i++) {
 911                 vq = &v->vqs[i];
 912                 if (vq->call_ctx.producer.irq)
 913                         irq_bypass_unregister_producer(&vq->call_ctx.producer);
 914         }
 915 }
 916
 917 static int vhost_vdpa_release(struct inode *inode, struct file *filep)
 918 {
 919         struct vhost_vdpa *v = filep->private_data;
 920         struct vhost_dev *d = &v->vdev;
 921
 922         mutex_lock(&d->mutex);
 923         filep->private_data = NULL;
 924         vhost_vdpa_reset(v);
 925         vhost_dev_stop(&v->vdev);
 926         vhost_vdpa_iotlb_free(v);
 927         vhost_vdpa_free_domain(v);
 928         vhost_vdpa_config_put(v);
 929         vhost_vdpa_clean_irq(v);
 930         vhost_dev_cleanup(&v->vdev);
 931         kfree(v->vdev.vqs);
 932         mutex_unlock(&d->mutex);
 933
 934         atomic_dec(&v->opened);
 935         complete(&v->completion);
 936
 937         return 0;
 938 }
 939
 940 #ifdef CONFIG_MMU
 941 static vm_fault_t vhost_vdpa_fault(struct vm_fault *vmf)
 942 {
 943         struct vhost_vdpa *v = vmf->vma->vm_file->private_data;
 944         struct vdpa_device *vdpa = v->vdpa;
 945         const struct vdpa_config_ops *ops = vdpa->config;
 946         struct vdpa_notification_area notify;
 947         struct vm_area_struct *vma = vmf->vma;
 948         u16 index = vma->vm_pgoff;
 949
 950         notify = ops->get_vq_notification(vdpa, index);
 951
 952         vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
 953         if (remap_pfn_range(vma, vmf->address & PAGE_MASK,
 954                             notify.addr >> PAGE_SHIFT, PAGE_SIZE,
 955                             vma->vm_page_prot))
 956                 return VM_FAULT_SIGBUS;
 957
 958         return VM_FAULT_NOPAGE;
 959 }
 960
 961 static const struct vm_operations_struct vhost_vdpa_vm_ops = {
 962         .fault = vhost_vdpa_fault,
 963 };
 964
 965 static int vhost_vdpa_mmap(struct file *file, struct vm_area_struct *vma)
 966 {
 967         struct vhost_vdpa *v = vma->vm_file->private_data;
 968         struct vdpa_device *vdpa = v->vdpa;
 969         const struct vdpa_config_ops *ops = vdpa->config;
 970         struct vdpa_notification_area notify;
 971         unsigned long index = vma->vm_pgoff;
 972
 973         if (vma->vm_end - vma->vm_start != PAGE_SIZE)
 974                 return -EINVAL;
 975         if ((vma->vm_flags & VM_SHARED) == 0)
 976                 return -EINVAL;
 977         if (vma->vm_flags & VM_READ)
 978                 return -EINVAL;
 979         if (index > 65535)
 980                 return -EINVAL;
 981         if (!ops->get_vq_notification)
 982                 return -ENOTSUPP;
 983
 984         /* To be safe and easily modelled by userspace, We only
 985          * support the doorbell which sits on the page boundary and
 986          * does not share the page with other registers.
 987          */
 988         notify = ops->get_vq_notification(vdpa, index);
 989         if (notify.addr & (PAGE_SIZE - 1))
 990                 return -EINVAL;
 991         if (vma->vm_end - vma->vm_start != notify.size)
 992                 return -ENOTSUPP;
 993
 994         vma->vm_ops = &vhost_vdpa_vm_ops;
 995         return 0;
 996 }
 997 #endif /* CONFIG_MMU */
 998
 999 static const struct file_operations vhost_vdpa_fops = {
1000         .owner          = THIS_MODULE,
1001         .open           = vhost_vdpa_open,
1002         .release        = vhost_vdpa_release,
1003         .write_iter     = vhost_vdpa_chr_write_iter,
1004         .unlocked_ioctl = vhost_vdpa_unlocked_ioctl,
1005 #ifdef CONFIG_MMU
1006         .mmap           = vhost_vdpa_mmap,
1007 #endif /* CONFIG_MMU */
1008         .compat_ioctl   = compat_ptr_ioctl,
1009 };
1010
1011 static void vhost_vdpa_release_dev(struct device *device)
1012 {
1013         struct vhost_vdpa *v =
1014                container_of(device, struct vhost_vdpa, dev);
1015
1016         ida_simple_remove(&vhost_vdpa_ida, v->minor);
1017         kfree(v->vqs);
1018         kfree(v);
1019 }
1020
1021 static int vhost_vdpa_probe(struct vdpa_device *vdpa)
1022 {
1023         const struct vdpa_config_ops *ops = vdpa->config;
1024         struct vhost_vdpa *v;
1025         int minor;
1026         int r;
1027
1028         /* Currently, we only accept the network devices. */
1029         if (ops->get_device_id(vdpa) != VIRTIO_ID_NET)
1030                 return -ENOTSUPP;
1031
1032         v = kzalloc(sizeof(*v), GFP_KERNEL | __GFP_RETRY_MAYFAIL);
1033         if (!v)
1034                 return -ENOMEM;
1035
1036         minor = ida_simple_get(&vhost_vdpa_ida, 0,
1037                                VHOST_VDPA_DEV_MAX, GFP_KERNEL);
1038         if (minor < 0) {
1039                 kfree(v);
1040                 return minor;
1041         }
1042
1043         atomic_set(&v->opened, 0);
1044         v->minor = minor;
1045         v->vdpa = vdpa;
1046         v->nvqs = vdpa->nvqs;
1047         v->virtio_id = ops->get_device_id(vdpa);
1048
1049         device_initialize(&v->dev);
1050         v->dev.release = vhost_vdpa_release_dev;
1051         v->dev.parent = &vdpa->dev;
1052         v->dev.devt = MKDEV(MAJOR(vhost_vdpa_major), minor);
1053         v->vqs = kmalloc_array(v->nvqs, sizeof(struct vhost_virtqueue),
1054                                GFP_KERNEL);
1055         if (!v->vqs) {
1056                 r = -ENOMEM;
1057                 goto err;
1058         }
1059
1060         r = dev_set_name(&v->dev, "vhost-vdpa-%u", minor);
1061         if (r)
1062                 goto err;
1063
1064         cdev_init(&v->cdev, &vhost_vdpa_fops);
1065         v->cdev.owner = THIS_MODULE;
1066
1067         r = cdev_device_add(&v->cdev, &v->dev);
1068         if (r)
1069                 goto err;
1070
1071         init_completion(&v->completion);
1072         vdpa_set_drvdata(vdpa, v);
1073
1074         return 0;
1075
1076 err:
1077         put_device(&v->dev);
1078         return r;
1079 }
1080
1081 static void vhost_vdpa_remove(struct vdpa_device *vdpa)
1082 {
1083         struct vhost_vdpa *v = vdpa_get_drvdata(vdpa);
1084         int opened;
1085
1086         cdev_device_del(&v->cdev, &v->dev);
1087
1088         do {
1089                 opened = atomic_cmpxchg(&v->opened, 0, 1);
1090                 if (!opened)
1091                         break;
1092                 wait_for_completion(&v->completion);
1093         } while (1);
1094
1095         put_device(&v->dev);
1096 }
1097
1098 static struct vdpa_driver vhost_vdpa_driver = {
1099         .driver = {
1100                 .name   = "vhost_vdpa",
1101         },
1102         .probe  = vhost_vdpa_probe,
1103         .remove = vhost_vdpa_remove,
1104 };
1105
1106 static int __init vhost_vdpa_init(void)
1107 {
1108         int r;
1109
1110         r = alloc_chrdev_region(&vhost_vdpa_major, 0, VHOST_VDPA_DEV_MAX,
1111                                 "vhost-vdpa");
1112         if (r)
1113                 goto err_alloc_chrdev;
1114
1115         r = vdpa_register_driver(&vhost_vdpa_driver);
1116         if (r)
1117                 goto err_vdpa_register_driver;
1118
1119         return 0;
1120
1121 err_vdpa_register_driver:
1122         unregister_chrdev_region(vhost_vdpa_major, VHOST_VDPA_DEV_MAX);
1123 err_alloc_chrdev:
1124         return r;
1125 }
1126 module_init(vhost_vdpa_init);
1127
1128 static void __exit vhost_vdpa_exit(void)
1129 {
1130         vdpa_unregister_driver(&vhost_vdpa_driver);
1131         unregister_chrdev_region(vhost_vdpa_major, VHOST_VDPA_DEV_MAX);
1132 }
1133 module_exit(vhost_vdpa_exit);
1134
1135 MODULE_VERSION("0.0.1");
1136 MODULE_LICENSE("GPL v2");
1137 MODULE_AUTHOR("Intel Corporation");
1138 MODULE_DESCRIPTION("vDPA-based vhost backend for virtio");